package org.apache.maven.model.management;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.maven.model.Dependency;
import org.apache.maven.model.DependencyManagement;
import org.apache.maven.model.Exclusion;
import org.apache.maven.model.Model;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.component.annotations.Component;

/**
 * Handles injection of dependency management into the model.
 *
 * @author Benjamin Bentmann
 */
@Component(role = DependencyManagementInjector.class)
public class DefaultDependencyManagementInjector implements DependencyManagementInjector {

  private ManagementModelMerger merger = new ManagementModelMerger();

  public void injectManagement(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
    merger.mergeManagedDependencies(model);
  }

  protected static class ManagementModelMerger extends MavenModelMerger {

    public void mergeManagedDependencies(Model model) {
      DependencyManagement dependencyManagement = model.getDependencyManagement();
      if (dependencyManagement != null) {
        Map<Object, Dependency> dependencies = new HashMap<Object, Dependency>();
        Map<Object, Object> context = Collections.emptyMap();

        for (Dependency dependency : model.getDependencies()) {
          Object key = getDependencyKey(dependency);
          dependencies.put(key, dependency);
        }

        for (Dependency managedDependency : dependencyManagement.getDependencies()) {
          Object key = getDependencyKey(managedDependency);
          Dependency dependency = dependencies.get(key);
          if (dependency != null) {
            mergeDependency(dependency, managedDependency, false, context);
          }
        }
      }
    }

    @Override
    protected void mergeDependency_Optional(Dependency target, Dependency source, boolean sourceDominant,
        Map<Object, Object> context) {
      // optional flag is not managed
    }

    @Override
    protected void mergeDependency_Exclusions(Dependency target, Dependency source, boolean sourceDominant,
        Map<Object, Object> context) {
      List<Exclusion> tgt = target.getExclusions();
      if (tgt.isEmpty()) {
        List<Exclusion> src = source.getExclusions();

        for (Exclusion element : src) {
          Exclusion clone = element.clone();
          target.addExclusion(clone);
        }
      }
    }

  }

}
